Cyclic strabismus: what measured angle of strabismus should guide surgery?

Purpose: Here we aimed to describe seven pediatric patients with cyclic strabismus and report the outcome of their surgical treatment.Methods: Seven children with acquired esotropia manifesting in a 48-h cycle were included in the study. Four of them were boys, and three of them were girls. All cases had a large angle of deviation and associated suppression on the esotropic day and small angle of deviation with fusion on the other day. A complete ocular motility examination was performed for seven consecutive days. For all cases, we planned strabismus surgery according to the amount of deviation on the strabismic day. Postoperatively, the deviation angles were recorded at the first week, first month, and third month. Later, the patients were examined at 3-month intervals.Results: The mean age at presentation was 4.42 ± 3.69 years (1-12 years). The mean angle of esotropia at near fixation preoperatively was 36.4 ± 14.9 pd (prism dioptre) (20-60 pd) on the esotropic day. The mean angle of esotropia on the esotropic day at distance fixation was 32.1 ± 6.9 pd (20-40 pd). The mean follow-up period was 18.4 ± 5.5 months (12-25 months). The mean duration of esotropia before surgery was 11.1 ± 9.4 months (3-29 months). Following surgery, orthophoria within 10 pd was achieved and maintained in all cases.Conclusion: When treating children with cyclic strabismus, the best surgical results can be achieved when surgery is planned according to the amount of deviation on the strabismic day.